DE202022001857U1 - Shredding machine with effective and gentle conveying for raw materials of animal or plant origin - Google Patents

Abstract

Chopping machine for raw materials of animal or vegetable origin, preferably meat, with an effective and particularly material-friendly mode of operation, hereinafter referred to as a chopping machine, characterized in that it has a combination of different augers (1) for feeding the tools of the cutting set (2) and separates them and can be driven (9, 10, 11) at variable speeds.

Description

State of the art:

In the case of shredding machines that work according to the Wolf principle, the raw material to be shredded, preferably meat, is fed to the cutting set as a rule by one or two screw conveyors.

So far it has been assumed that the thrust pressure is generated by the feed screws used and is therefore the causal prerequisite for the achievable throughput of the grinder.

It is assumed that the penetration of the pieces of meat into the bores as meat plugs is a purely pressure-dependent variable of the originally larger-sized raw material state. This is therefore directly related to the arrangement of the holes on the disc surface.

Thus, pressure-increasing, single-flight worm systems with decreasing worm chamber volume in the direction of the cutting set are preferred.

The crushing effect to which the raw material is subjected during the conveying process as a result of its task of power transmission generally receives little attention.

Destruction of the raw material occurs here, which can lead to a reduction in the generation of thrust and to its return flow.

Seen in this way, different strength properties of the material to be processed are compensated for and no differentiation is discernible when it emerges from the cutting set.

The strength of the raw materials is completely different if the conveying process is carried out with a system that does not change the material to be processed in the course of feeding, because the screws have the same chamber volume and processing only takes place after the screws have left the tool system due to the thrust pressure that occurs without backflow.

Here the full strength potential of the structure of the material to be shredded only has to be overcome by higher pressure when pressing into the disc-knife system of the cutting set.

It is noticeable that the raw material has large differences in strength in its grown structure and that completely different peg lengths are produced depending on the type of material.

It is particularly critical in the case of processed goods in the deep-frozen state, the firmness of which is much higher due to the freezing and for which no cones can form at all with pure pressure.

There are no test results available for the processing of deep-frozen meat with conventional twin-screw grinding technology and a final perforated disc with a diameter of 3 mm.

The tools in the cutting set and the strength of the material to be processed offer great resistance to the formation of cones in the perforated discs.

As a result, typical grinding worms with power transmission between the worm and the housing lead to heating, raw material reflux, mixing and a reduction in material strength.

Only with an increase in temperature, a reduction in strength due to heating and destruction of the structure is it possible to form cones in the cutting set and to discharge comminuted processing material from the end perforated disc.

In the case of deep-frozen meat, for example, this is only the case when there is a difference of approx. 14 degrees to the outlet temperature from the perforated disc.

The reduction in structural strength with the increase in raw material temperature occurs in connection with mechanical work in the power transmission of the raw material feed with the predominantly used working screws when conveying to the cutting tools.

Typical working properties are the raw material reflux and the mixing processes in the screw area.

The conditions for penetrating the perforated discs of the cutting set are formed by the pure thrust pressure resulting from the resistance of the tools and the material structure as a reaction to the material supply when carrying out the comminution work.

As a result, with the known thrust pressures at low raw material temperatures, it is no longer possible to produce a starting product with a very small grain size, because the typical active element free space in front of the cutting set tools is clogged with compacted processing material.

This load occurs when conveying with extruder screws that are sealed to the housing wall of the material to be processed with regard to its structural strength and temperature condition.

In the predominantly used grinding machines with the arrangement of a feed screw and a subsequent working screw, the coarse raw material is accepted by a rotating screw body in the funnel of the grinding machine.

The raw material is held on the hopper wall.

Here, the rotating worm body draws in the pieces of meat on one side and conveys them into the closed working worm housing.

The collected raw material is pressed in the direction of the outlet with the conveying movement by the thrust pressure of the rotating screws.

The cutting set arranged there takes over the cutting from the disc bores with rotating knives.

With the one-sided raw material intake, high deformation forces occur on the worm when raw material is drawn in from the funnel, the worm shaft supported on one side bends and is pushed out of the middle of the barrel.

This is the cause of canting and bending of the knife pin and there is increased wear on the knives and perforated discs.

In general, the manufacturers of mincers regard the knife pin as the second bearing point of the worm in the cutting set.

In reality, the knife pin is a separate drive and bearing point for the cutting system, which represents a particular weak point and the elimination of bending due to a lack of space in the middle of the disc cannot be achieved by reinforcement.

It is driven only by a weak connection for power transmission between the worm shaft and the journal.

If one omits the bend in the journal, one can see that the cross-sections for power transmission of the two shafts are not able to guarantee complete worm bearing for the raw material supply and transfer to the cutting set system.

According to tests carried out, the knife pins are only suitable for processing fresh raw materials.

With deep-frozen raw materials, the cross-sectional geometry of the two-edged profile is no longer sufficient for the knife forces that occur.

It would be an increase in the cross-section of the knife tang with an impact on the dimensions of the entire cutting set, i. H. Reduction of the working geometries of the tools and thus the machine performance necessary.

However, this must be ruled out, since the cutting part sizes are fixed worldwide.

The bending of the auger and blade pivot is the cause of the tool tilting due to insufficient storage or number of equivalent bearings in the dimension of the drive bearing of the grinder.

This results in increased wear and the destruction of parts of the machine, mainly the worm, the housing and the tools.

The weak point - connection of the own knife pin shaft for the tools as a drive in the working worm shaft is the completely wrong arrangement of the worm bearing and the stability of the worm shaft against the forces of drawing the raw material into the working housing.

The knife pin should form a second bearing point and at the same time drive the tools. It is built into the snail for this purpose.

This double function in the knife pin cannot be fulfilled due to the different effective forces.

The tools, on the other hand, are used in their own tool housing and are mounted and clamped vertically with the knives.

The tool housing is a separate assembly and the storage location for the tools.

It is only functionally connected to the auger housing and has no established function for auger storage.

Goal:

With a combination of different augers for the feed to the tools of the cutting set and use of their properties, an optimal adaptation of the active assemblies of a shredding machine working according to the mincer principle to all types of processed goods and the respective different states should be possible.

This should significantly expand the range of applications while complying with high demands on wear-free and trouble-free functionality, effectiveness of the machine and quality of the end product through use in different machine sizes.

Task:

The task is to be solved in such a way that the feeding of the raw material up to
cutting set is divided into sections for the raw material intake in the hopper, transfer, transport chamber with backflow prevention and pre-shredding to reduce strength and the screw conveyors in these sections each have geometric shapes tailored to the purpose, as well as separately and at variable speeds, but also driven together in a network if necessary will.
At the same time, the bearing conditions of the worms are to be improved in order to avoid tilting and to significantly reduce wear on the cutting set components.

Description:

The task is solved by the fact that the screw feed from the funnel to the cutting set consists of three areas with different screw segments, the modules of which are designed according to the raw material to be processed with divided functions in required lengths and with defined properties.
The screw modules are separated and driven at variable speeds (9,10,11).

The raw material passes from the hopper (3) and the transfer area (4) into the area of the transport chamber (5), which no longer allows material to flow back and is also referred to below as the locking screw area.

In the subsequent zone of strength reduction (6), the screw is provided with elements for pre-crushing (8).

All screw elements are interchangeable and their geometric design can be optimally adapted to the different processed goods and to the end product to be achieved.

A pressure sensor (13) arranged in front of the cutting set (2) ensures variable speed regulation of the augers and a metered feed quantity through the transport chamber (5) in order to only convey as much material as the cutting set can hold.

In this area, the double-arranged screws work as compression-free displacement screws, which convey the raw material without changing the energy input. The conveying process applies to all states of the various processing goods and quantities.

It is not necessary to fill the screws to a high degree, since the material to be conveyed is pushed further with the spiral shape of the displacement geometry of both screws.

The worm screws seal each other up to 98% with worm threads on their shafts.

This prevents material from flowing back as a result of the impact of the dynamic pressure that is generated in the pre-shredding area (6) in front of the cutting set (2).

The conveying process of the locking screws is carried out by the spiral-shaped screw chambers, which roll into one another according to the principle of volume displacement, without mechanically stressing the material to be processed, regardless of the degree of filling.

The degree of filling of the screw chambers is irrelevant.

Both 100% and close to 0% material to be conveyed are moved evenly.

In addition to the speed adjustment, this is the prerequisite for dosing the feed quantities.

The bearing of the worms is improved by a dynamic bearing system on the housing wall (7), because the deformation of the worms due to the forces acting when the raw material is drawn in is significantly reduced.
In this way, high wear of the cutting tools up to and including destruction of the auger and the auger housing due to lateral deflection of the knife pin is ruled out.

The reasons for the previous insufficient bearing lie in the lack of bearing dimensioning of a second bearing point for the working worm, in the large distance between the bearing points in the worm drive, in the cutting set with the knife pin as a replacing bearing point for the worm and the worm housing with the support profiles.

A reinforcement of the pin is only possible to a limited extent, since the technical environment is defined by the worldwide tool and walking External dimensions cannot be dimensioned according to the forces occurring when the raw materials are received, without negatively changing large functional parts of the tool dimensions.

It requires a bearing with shortened lever arms for the application of force and a bearing surface that can absorb the forces that arise without including the knife pin in the force absorption.

The task is solved in that the function-related, wear-generating worms and worm housings are exchanged for a conveyor system with which the bearing function is taken over directly by the worms and in the housing.

For this purpose, the pairing of materials between the two parts is selected in such a way that a plain bearing pairing is created that almost completely eliminates wear, in that the bearing function is matched to the length of the worm and the number of worm threads to the length of the housing.

With this form of taking over the storage task, the lever lengths when drawing in the raw materials are reduced by a factor of 3 to 5, the drawing-in forces are placed centrally on two shafts and the force acting on the individual shaft is halved.

On the drive side, there are shafts that meet the conditions of a cantilever shaft bearing with a significantly higher level of bearing safety.

Additional cutting elements (8) adapted to the raw material for pre-crushing and mixing with heat exchange are arranged in the area for reducing strength (6) between the conveying screw flights.

The material to be processed is fed into the hopper area (3) with open screw elements whose task is to accept the raw material and feed it to the blocking screw area (5).

The screw threads are designed in such a way that, in addition to the conveying function, they also serve to roughly break up the structure for the purpose of easier transfer to the locking screws (5).

The drives (9, 10, 11) work separately or are coupled for specific tasks.

For a desired entrainment of the worm for pre-shredding (6) by the working and locking worms (5), both worms are mechanically connected to each other after replacing the pre-shredding worm (6) and the drive (11) of the pre-shredding worm is separated by the clutch (12).

The speed adjustments between the different screws ensure a variable conveying function with the setting of the quantity feed and the time required for the desired shredding.

The point here is to achieve a reduced firmness of the material to be processed, such as meat, in the space (6) in front of the cutting set (2), which ensures that cones are formed in the perforated discs of the cutting set.

Cone formations are deformations in a piece of raw material with grown structures of varying strength.

Overcoming these strength structures requires a load that tears, or at least loosens, the bond in the fabric parts that lie directly on the perforated disk. Only then can pegs be shaped freely into the bores.

When using the well-known normal grinding augers, a backflow always occurs, since the conveying efficiency is about 30 to 50% lower due to the lack of functional tightness of these augers to the housing wall.

As a result, large parts of the conveyed quantities are not removed from the cutting set. In this way, under the auger in the support system, there is a backflow of already loaded and partially destroyed parts of the processed material.

Due to their sealing properties, the locking screws ensure that the material to be processed remains only in this work area and ensure the strength-related change in the material state as a prerequisite for penetration into the holes in the perforated disc.

In the pre-shredding area (6), the tightly bound, grown and highly elastic material structures are broken up by deliberately volume-controlled conveying of the locking screws.

As a result, a solid material structure can also be heated at very low temperatures, for example in the frozen state, by the input of conveying work and broken up by tearing.

Depending on the condition of the raw material, a casing (14) of the screw housing (7) also enables the supply of heat energy, which It can take the form of water, oil, induction, microwaves or ultrasonic excitation.

With controlled load work using the return flow of raw materials in space (6), a deformable material state and a state of the processed material that can be accepted by the tool system are established.

When using the usual, known, grinding worms for deep-frozen processing material, there is an imbalance between the quantity supplied and the removal capacity of the cutting set.

This means that it cannot be included in the cutting set for further comminution.

It presupposes an increase in pressure through metered feed quantities from the locking screws, which then presses the destroyed processing material into and through the cutting set in space (6).

This behavior is used with deep-frozen material, such as meat, to achieve the penetration properties into the bores through mechanical stress with heating.

With the help of the pressure sensor (13) in the area in front of the cutting set and the machine control, the speed of the worms can be adjusted and a corresponding material feed and a constant processing state with the material property for peg formation in the holes of the perforated disc can be generated.

Further advantageous configurations of the invention result from the invention claims, the description and the drawing 1 .

reference list

1

Combination of different snails

2

blade set

3

Hopper for raw material intake

4

transfer area

5

Transport chamber as an area to prevent backflow

6

Pre-shredding area for strength reduction

7

housing wall

8th

pre-shredding elements

9

Drive for working and locking worm

10

Drive for feed screw

11

Drive for worm for strength reduction

12

shifting clutch

13

pressure sensor

14

Sheathing for snail housing

Claims (9)

Chopping machine for raw materials of animal or vegetable origin, preferably meat, with an effective and particularly material-friendly mode of operation, hereinafter referred to as a chopping machine, characterized in that it has a combination of different screws (1) for feeding to the tools of the cutting set (2) and separates them and can be driven (9, 10, 11) at variable speeds. shredding machine claim 1 , characterized in that the feed to the cutting set consists of the sections raw material intake in the hopper (3), transfer (4), transport chamber (5) and pre-shredding (6) and the screw conveyors in these sections each have geometric shapes tailored to the purpose. Shredding machine according to claims 1 and 2 , characterized in that the aisles of the duplicate screws in the transport chamber (5) are designed as a dynamic bearing system for the housing wall (7) with regard to material, width and number and their lengths are adapted to the product-typical properties. Shredding machine according to claims 1 , 2 and 3 , characterized in that the screws in the transport chamber (5) are made of plastic and have a pair of materials with coordinated sliding properties to the inner wall of the housing (7). Shredding machine according to claims 1 and 2 , characterized in that the pre-crushing zone consists of a space in which pre-crushing elements (8) adapted to the raw material to be processed are arranged on the base body of the screw conveyor. Shredding machine according to claims 1 , 2 and 5 , characterized in that all active elements are performance- and task-related interchangeable. Shredding machine according to claims 1 until 6 , characterized in that all working elements in the sections can be driven individually, but if necessary also in combination (9, 10, 11). Crushing machine according to the preceding claims, characterized in that a sensor (13) for detecting the current pressure is arranged in the zone of reduction in strength (6). Shredding machine according to the preceding claims, characterized in that the sensor (13) is connected to a controller for regulating the screw speeds and an external supply of heat energy in a casing (14) of the screw housing (7), which is in the form of water, oil , induction, microwave or ultrasonic excitation can take place.

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